What it reads

Languages, frameworks and formats

Support is per-signal rather than per-language: a repository in an unlisted language still gets containers, deployment topology and evidence from its manifests and Dockerfiles — it just gets no API contracts or flows.

Languages

Parsed with tree-sitter for symbols, calls, imports and types.

Language	Module layout read from
Rust	Cargo workspaces and crates
TypeScript / JavaScript	npm and workspace packages
Go	Go modules and package directories
Python	Packages, uv and Poetry workspaces
Java	Maven and Gradle modules
Kotlin	Gradle modules
C#	`.csproj` projects, named by `AssemblyName` or the file

A file in any other language still counts towards a unit and its Dockerfile, and the book says plainly which parts were not parsed.

HTTP and RPC

Where operations, parameters, request and response models and callers come from.

Go	chi, Echo, Gin, Fiber, gorilla/mux, `net/http`
TypeScript	Express, Fastify, Koa, Hono, NestJS
Python	FastAPI, Flask, Django, Starlette, aiohttp
Rust	Axum, Actix Web, Rocket, warp, Poem
JVM	Spring MVC, Spring WebFlux, JAX-RS, Quarkus, Micronaut, Dropwizard, Jersey, Helidon, Javalin, Vert.x, Ktor
C#	ASP.NET Core attribute-routed controllers and minimal-API `Map*` routes
Service-to-service	Feign, MicroProfile Rest Client, Micronaut clients, gRPC stubs, and HTTP client calls matched to the operation they hit
Gateways	Spring Cloud Gateway and Zuul routes read from configuration, including routes declared in a config server

Data

ORMs and mappers	JPA/Hibernate, Spring Data, jOOQ, MyBatis, JDBI, Micronaut Data, Panache, Exposed, EF Core, GORM, sqlx, `database/sql`, Diesel, SeaORM, Prisma, TypeORM, Sequelize, Drizzle, Kysely, Knex, SQLAlchemy, SQLModel, Django ORM, Peewee, Tortoise
Migrations	Liquibase, Flyway, Alembic, raw SQL
Stores	PostgreSQL, MySQL, SQLite, MongoDB, Redis, Elasticsearch, S3, Firestore, DynamoDB
Read from them	Entities, columns, keys, cardinality, which service reads and which writes, and lifecycles inferred from status fields plus the code that changes them

Messaging and background work

Brokers	Kafka, RabbitMQ, NATS, SQS, Google Pub/Sub
In-process events	Spring `publishEvent`, `@EventListener`, Spring Modulith `@ApplicationModuleListener`, Micronaut events
Schedules	`@Scheduled` and cron expressions, resolved through configuration placeholders
Traced	A published event is followed into the handlers that consume it, across services

Deployment

Docker Compose	Services, builds, images, ports, volumes, profiles, health checks, `depends_on`, `.env` substitution, and overlay files layered with `-f`
Kubernetes	Deployment, StatefulSet, DaemonSet, Job, CronJob, Service and Ingress, found by content anywhere in the repository
Helm	Value-only templates rendered; a template needing control flow is reported as not read rather than guessed at
Third-party services	Stripe, SendGrid, Twilio, OpenAI, Anthropic, Slack and SMTP, from the client libraries that call them

Known gaps

Authentication applied by middleware, rather than per route, is not attributed to the operations it protects.
A port with several implementations is left unresolved rather than guessed. Which one a service uses is often decided by dependency-injection wiring at startup, which is not in the source — so a request flow through such a port stops at the port.
A call into a library the service links is not followed, so work a shared package does on the service's behalf does not appear as a step in its flows.
ASP.NET Core routes are read from attributes. A controller routed by convention through MapControllerRoute declares its paths in a pattern string rather than on the action, so those operations are not found — the pattern says where a class of routes lives, not which ones exist.

The rules behind each of these — how units, compose services, calls, datastores and events are recognised, and where each stops — are written out in HEURISTICS.md.

Something missing or wrong for your stack is worth an issue — the templates are built around exactly those two cases.